Measurement and analysis of vibrations - Evaluation of the criteria of acceptance ISO Standard 10816-6
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Measurement and analysis of vibrations - Evaluation of the criteria of acceptance ISO Standard 10816-6 Medición y análisis de vibraciones – Evaluación del criterio de aceptación Norma ISO 10816-6. DOI: https://doi.org/10.25043/19098642.196 Roger Arévalo Gómez 1 Abstract During the reception and / or delivery tests of a ship, vibration measurement and analysis is made to the propulsion line in order to evaluate and predict the condition of the machinery. The values taken during the measurement of the vibrations are evaluated with the acceptance criteria provided by the standards. International Standard ISO 10816-6 (1995) focuses on reciprocating machinery with power of greater than 100kW, is used by both analysts and manufacturers of propulsion machinery for ships. Through this work, we intend to evaluate the acceptance criteria of this norm in boats smaller than 100 meters. At the end of this work it is concluded that the standard must be updated, indicating and differentiating the acceptance criteria for machinery taking into account its type of anchorage to the structure (flexible or rigid), boats with length less than or greater than 100 meters and the Ship building material (Aluminum, Steel or Composite material). Key words: Reciprocant, Vibration level. Resumen Durante las pruebas de recepción y/o entrega de un buque se realiza medición y análisis de vibración a la línea de propulsión con el fin evaluar y predecir la condición de la maquinaria. Los valores tomados durante la medición de las vibraciones son evaluados con los criterios de aceptación que entregan las normas. La norma Internacional ISO 10816-6 (1995) se enfoca en la maquinaria reciprocante con potencia de rateo mayor a 100kW, es utilizada tanto por analistas como por fabricantes de maquinaria propulsiva para buques. Por medio de este trabajo se pretende evaluar los criterios de aceptación de esta norma en embarcaciones menores a 100 metros. Al final de este trabajo se concluye que la norma debe ser actualizada, indicando y diferenciando los criterios de aceptación para maquinaria teniendo en cuenta su tipo de anclaje a la estructura (flexible o rígida), embarcaciones con eslora inferior o superior a 100 metros y el material de construcción del buque (Aluminio, Acero o Material compuesto). Palabras claves: Reciprocante, nivel de vibración. Date Received: January 17th 2019 - Fecha de recepción: Enero 17 de 2019 Date Accepted: March 3rd 2019 - Fecha de aceptación: Marzo 3 de 2019 1 COTECMAR. Cartagena, Colombia. Email: rarevalo@cotecmar.com Ship Science & Technology - Vol. 13 - n.° 26 - (39-44) January 2020 - Cartagena (Colombia) 39
Roger Arévalo Gómez Introduction Therefore, it was determined to reclassify the machinery at least to level 3 indicated by ISO 10816-6 "Mechanical vibration - Evaluation the standard. By doing this, we had a more of machine vibration by measurements on non- accurate alarm of the novelties presented by the rotating parts - Part 6: Reciprocating machines diesel machinery and determined through the with power ratings above 100 kW", specifies measurement and analysis of linear vibrations. the conditions and general procedures for the measurement and evaluation of the linear vibrations, in measurements made on the non- Presentation of the problem rotating parts of reciprocating machines with powers greater than 100 kW. Before COTECMAR, had the ability to meet the service of measurement and analysis of vibrations Typical examples of application are marine lines with its own strength, this was executed by propulsion engines, Diesel engine generator sets, means of contractors, local companies specialized in gas compressors and diesel engines for locomotives. measurement and analysis of vibrations, but who did This standard does not apply to machines installed not have the knowledge in the area ship, the behavior of on road vehicles. the marine combustion machinery and the standards used by these companies were not adequate. ISO 10816-6 in Annex A "Classification of vibration in machinery" indicates a qualification The ignorance in the behavior in marine diesel of reciprocating machinery. In said classification, machinery and the lack of use of an adequate the standard establishes that diesel and industrial norm in multiple occasions caused complaints and marine engines can be classified either 5, 6 or 7. complaints on the part of the final client due to a bad concept or conclusion on the part of the analyst. Since 2013, COTECMAR has acquired the technological and human capacity to carry out By training personnel in the naval area, certifying with its own force the measurement and analysis it in vibration analysis under the guidelines of ISO of the linear vibrations of the ships belonging 18436-2 in level II and acquiring equipment for to the Colombian Republic Navy (ARC) and the measurement and subsequent analysis of the private customers. linear vibration measurement, gave COTECMAR a better answer. customers, reducing the number In these more than four years the experience in the of complaints and claims, which was seen in a measurement and analysis of linear vibrations in significant increase in the number of services that the propulsion lines of ships has been strengthened, went from 9 in 2014, 42 in 2015, 46 in 2016, 40 in which includes an internal combustion engine, 2017 and 46 services in 2018. a power transmission box and revolutions to the transmission shaft and finally to the propeller. For the analysis of measured vibrations, the criteria of ISO 18816 and its six different parts are taken as In more than 63 ships served in this period (2013 acceptance criteria: to 2018) measurements and analysis of linear vibrations were made to diesel engines of ARC and • Part 1: General guidelines. private vessels, totaling approximately 150 services. • Part 2: Large steam turbine generator sets on At the beginning there were many inconveniences land exceeding 50 MW. and complaints from the client because although • Part 3: Industrial machines with nominal the global vibrations did not reach the minimum power greater than 15 kW and rated speeds level, level 5, required by ISO 10816-6 to consider between 120 r / min and 15 000 r / min when an alarm in the diesel machinery, in reality, there measured in situ. were developments in the engines, which affected • Part 4: Sets powered by gas turbines, excluding the credibility of the client. aircraft derivatives 40 Ship Science & Technology - Vol. 13 - n.° 26 - (39-44) January 2020 - Cartagena (Colombia)
Measurement and analysis of vibrations - Evaluation of the criteria of acceptance Norma ISO 10816-6 • Part 5: Sets of machines in hydraulic generating The values of the vibration measurements were and pumping plants. taken in the diesel combustion engines according • Part 6: Reciprocal machines with nominal to ISO 10816-6 [1]. powers greater than 100 kW. Fig. 1. Diesel engine in L. In order to evaluate the vibrations measured in the propulsion lines of the ships, ISO 10816- 3[2] standards are adopted for gearboxes, support points and bearings and ISO 10816-6 [1] for the evaluation of propulsion engines. The norm ISO 10816-3 [2] establishes criteria for the levels of the linear vibrations measured according to the power, revolutions per minute of rotation and type of support or anchoring of the equipment (flexible, rigid or semi-rigid). The norm ISO 10816-6[1] classifies the vibration of the machinery in seven levels. The standard does not indicate how to classify the machinery that is being measured. It only indicates that as an example many industrial and marine Diesel engines are classified 5, 6 and 7. But it does not give more details. Manufacturers of marine engines such as Wartsilla and MTU give a rating of 5 to their engines. Fig. 2. Multi-cylinder Diesel engine in V. Measured Data 1 Between 2013 and 2018, more than 150 diesel combustion engines from different manufacturers and models have been vibrated. The following is a summary of the brands and models of diesel combustion engines serviced. Table 1. Summary of Brand and Model of Diesel 2 Engines serviced. BRAND - MODEL MTU - 12V M70 MTU - 1163 TB93 CATERPILLAR - 3412 CATERPILLAR - 3056 Points 1 and 2 are called free side and side coupling CATERPILLAR - C18 respectively. At each point the measurement is made DETROIT DIESEL - 6L 2T in the three directions Vertical (V), Horizontal DETROIT DIESEL - 6L 71T (H) and Axial (A). DETROIT DIESEL - 16-645 E2 MAN B&W - 6L23/30A The data taken is compared with the classifications CUMMINS and acceptable levels given in ISO 10816-6 [1]. Ship Science & Technology - Vol. 13 - n.° 26 - (39-44) January 2020 - Cartagena (Colombia) 41
Roger Arévalo Gómez Fig. 3. Comparison of global vibration values with the acceptance criteria according to ISO 10816-6. MEDICIONES GLOBALES DE VIBRACIÓN EN RMS (mm/s) 80,00 1-H 1-A 70,00 1-A 2-H 2-V 60,00 2-A Clasificacion 1 50,00 Clasificacion 2 Clasificacion 3 40,00 Clasificacion 4 Clasificacion 5 30,00 Clasificacion 6 Clasificacion 7 20,00 10,00 0,00 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300 2400 2500 2600 2700 2800 RPM Fig. 4. Comparison - Values Of Global Vibration Vs Classification Levels - Motors Without Failure. 80,00 MEDICIONES GLOBALES DE VIBRACIÓN EN RMS (mm/s) 1-H 70,00 1-A 1-A 2-H 60,00 2-V 2-A 50,00 Clasificacion 1 Clasificacion 2 Clasificacion 3 40,00 Clasificacion 4 Clasificacion 5 30,00 Clasificacion 6 Clasificacion 7 20,00 10,00 0,00 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 RPM For the analysis, 23 vessels were taken into misalignments of engine parts, such as high levels account, each of which possesses two propulsion of cooling water temperature or low oil pressure, lines, so in total 46 engines were examined. As associated with a lack of maintenance. shown in illustration 6, of the 48% of the ships to which the global vibration measurements were If marine diesel engines continue to be evaluated taken, their engines present failure even with under ISO 10816-6[1] in the considerations vibration magnitudes below the classification 5 that this indicates, failures could arise due to an indicated in ISO 10816-6 [1]. These failures are erroneous decision, for example a propulsion related to sources other than poor installation or engine could be presented with vibration levels 42 Ship Science & Technology - Vol. 13 - n.° 26 - (39-44) January 2020 - Cartagena (Colombia)
Measurement and analysis of vibrations - Evaluation of the criteria of acceptance Norma ISO 10816-6 Fig. 5. Comparison - Global Vibration Values Vs Classification Levels - Faulty Engines. 80,00 MEDICIONES GLOBALES DE VIBRACIÓN EN RMS (mm/s) 70,00 1-H 1-A 60,00 1-A 2-H 50,00 2-V 2-A Clasificacion 1 40,00 Clasificacion 2 Clasificacion 3 30,00 Clasificacion 4 Clasificacion 5 20,00 Clasificacion 6 Clasificacion 7 10,00 0,00 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300 2400 2500 2600 2700 RPM Fig. 6. Comparison - Global Vibration Values Vs Classification Levels - Faulty Engines with Values below the Qualification 5. 80,00 MEDICIONES GLOBALES DE VIBRACIÓN EN RMS (mm/s) 1-H 70,00 1-A 1-A 60,00 2-H 2-V 2-A 50,00 Clasificacion 1 Clasificacion 2 40,00 Clasificacion 3 Clasificacion 4 Clasificacion 5 30,00 Clasificacion 6 Clasificacion 7 20,00 10,00 0,00 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 RPM above the classification 4 that was affecting the Conclusion structural integrity of the vessel. Or have a diesel combustion engine whose levels of vibration were There are engine failures, even if these have global above classification 5 but that did not present vibration levels below the minimum classification problems of mechanics, simply the base where it is suggested by ISO 10816-6[1], so the classification supported is flexible and the material of the vessel indicated by ISO 10816-6[1] should be modified, is made of aluminum or composite material. the standard should have the ability to indicate, as is Ship Science & Technology - Vol. 13 - n.° 26 - (39-44) January 2020 - Cartagena (Colombia) 43
Roger Arévalo Gómez the norm ISO 10816-3[2], the levels of acceptance (Temperature, Pressure) exceed the alarm according to their power, the type of anchoring of value. This is because for the vibration levels the engines, whether rigid or flexible and also the to be considered high or harmful, it is because construction material of the vessel. the machinery is suffering some affectation reflected in its temperature and operating The way of obtaining the accepted levels of pressure of Oil, Fuel, Cooling Water. vibration for marine diesel engines could be in two ways: With these values of vibration lines would be created more real acceptance levels and would • Establish a list of the linear vibration levels in help to make a more assertive diagnosis to diesel Diesel internal combustion engines installed propulsion engines. in new vessels, tabulating power, number of banks (1 or 2), propulsion line numbers, type of anchoring of the bases (Flexible, Rigid or References Semi-rigid) ) and material of the vessel (Steel, Aluminum or Composite Materials) and create 1. ISO. (15 de Diciembre de 1995). ISO 10816-6. a tendency to depart from said primary values Mechanical vibration -- Evaluation of machine by handling a first alarm (Caution) of 25% of vibration by measurements on non-rotating the initial value. parts -- Part 6: Reciprocating machines with power ratings above 100 Kw. • Set up a list of linear vibration levels in diesel 2. ISO. (15 de Mayo de 1998). ISO 10816- internal combustion engines after maintenance 3. Mechanical vibration — Evaluation of tabulating power, number of benches (1 or 2), machine vibration by measurements on non- propulsion line numbers, type of anchoring rotating parts — Part 3: Industrial machines of the bases (Flexible, Rigid or Semi-rigid) with nominal power above 15 kW and nominal and material of the vessel (Steel, Aluminum speeds between 120 r/min and 15 000 r/min or Composite Materials) and register the when measured in situ. vibration values when the operating parameters 44 Ship Science & Technology - Vol. 13 - n.° 26 - (39-44) January 2020 - Cartagena (Colombia)
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